The 13th Edition of HORIZONS means the proven Seeds/Backman approach and trusted content, fully updated with the latest discoveries and online resources to meet the needs of today's diverse learners. Focusing on two central questions: "What are we?", and "How Do We Know?" Seeds and Backman help students understand their place in the universe, and how scientists work. Cengage Learning has invested in our bestselling astronomy title to offer a range of digital solutions, including Enhanced WebAssign, unique author-written text- specific online tutorials, Virtual Astronomy Labs 2.0, and more. Whether you need a robust online learning system or a turn-key solution to engage students outside the classroom, HORIZONS 13E delivers!